I was making MLEB release bundle yesterday with Amir, and we noticed that neither of us have the ability to remove remote tags. I know for certain that Chad enabled this a while ago and it worked for me, so the ability seems to be lost at some point.
The output given from Gerrit is:
remote: You need 'Push' rights with the 'Force Push'
remote: flag set to delete references.
NB: We only want to delete MLEB tags we haven't announced yet ;)
Version: unspecified
Severity: normal
URL: https://code.google.com/p/gerrit/issues/detail?id=1902